Remotely operated manipulator



Aug. 15, 1961 E. 1.. HUTTO 2,996,330

REMOTELY OPERATED MANIPULATOR Filed Nov. 12, 1959 INVENTOR. Edwin L.Huffo ATTORNEY 2,996,330 REMOTELY OPERATED MANIPULATOR Edwin L. Hutto,Oak Ridge, Tenn., assignor to the United States of America asrepresented by the United States Atomic Energy Commission Filed Nov. 12,1959, Ser. No. 852,583 2 Claims. (Cl. 294-88) This invention relates toa means for performing, with in an entirely enclosed cell containingradioactive materials, various mechanical operationsspecifically thetransfer of radioactive samples from carrier to sampler and the openingof the same for analysis of the contents thereof.

Many manipulators, both simple and complex, have been developed in theprior art for accomplishing various operations with the isolated cellswherein radioactive materials are processed. Some of these manipulatorshave been mechanical, others pneumatic or hydraulic, still otherselectrical, and more often a mixture of these basic manipulating meanshave been used. Typical of these are the type which utilize a pantographtype of operation over the top of a wall of the cells to duplicateinside the cell the movements performed outside. This necessitates anopening in the cell. Another type uses a plurality of endless belts totransmit the motion. This also necessitates an opening into the cell.

A large proportion of the other prior art manipulators also require someopening into the cell through which some mechanical portion of themotion is accomplished. If these openings are placed so as to preventradiations from penetrating the same, such manipulators are useful formost radioactive materials. However, when the radioactive materials arevolatile or are easily scattered, as in the case of plutonium, the cellmust be completely closed, thus obviating the use of many of the priorart manipulators.

Some prior art manipulators are electro-mechanical and require noopenings through the cell wall, such as disclosed in U.S. Patent No.2,476,249. However, they are too complex for small operations. It isdesirable to provide a relatively inexpensive and simple manipulator foruse in a completely enclosed cell.

With a knowledge of the complexity of the prior art manipulators for usewith enclosed cells, it is a primary object of this invention to providea simple and inexpensive manipulator wherein the driver is positionedoutside a hot cell and the slave or driven portion is within the cell,and the cell is maintained airtight.

It is another object of this invention to provide a manipulator with aminimum of movable parts, which is simple to operate, and which isessentially leak free.

These and other objects and advantages of this invention will becomeapparent from a consideration of the following detailed specificationand the accompanying drawing, wherein:

The single figure is a cross sectional view of the manipulator designedto accomplish the above stated objects.

The above objects have been accomplished in the present invention byproviding a rod which is slidable within a tubular sleeve. The rod has apair of fingers affixed thereto which may be separated by relativemovement between the rod and sleeve. The rod and sleeve are enclosed ina tubular member, the rod being longer than the sleeve. A magneticfollower of magnetizable material is affixed to the end of the sleevethat extends out of the cell, and another magnetic follower is affixedto the end of the rod. A permanent magnet is enclosed in a sleeve memberwhich slides on the tubular member and the magnet is disposed adjacentto the magnetic follower fixed to the sleeve. Another permanent magnetis en- States Patent Q 2,996,330 Patented Aug. 15, 1961 closed inanother sleeve member slidable on the tubular member and the othermagnet is disposed adjacent to the magnetic follower fixed to the rod.The respective sleeve members are held in a fixed position with respectto each other by a compression spring so as to normally hold the fingerson the cell end of the rod closed. The sleeve members may be movedtoward each other to impart relative motion between the rod and sleeveto thus open the fingers. When the sleeve members are moved as a unit,the rod and sleeve may be moved in an axial direction, or be rotatedabout their axis by the action of the magnets upon the magneticfollowers. The tubular member enclosing said rod and sleeve is sealed toan opening in the cell by means of a flexible bellows in such a mannerthat additional motion may be imparted to the fingers in at least twoplanes.

Refer now to the drawing, which illustrates one embodiment in which theprinciples of this invention may be carried out. A central rod 1aextends centrally through the entire unit and terminates in formed tongfingers 1, which extend through a hole in one wall 33 of the cell.Encircling the rod 16; is a guide tube 2, and spaced coaxially therefromis a closure tube 3. A bushing 4- closes one end of the annulus betweenthe guide tube 2 and closure tube 3, and serves as a bearing for theguide tube 2. A plurality of openings 34 are provided in closure tube 3adjacent to bushing 4 to provide for move ment of air into and out' oftube 3 to allow freedom of movement of rod 111 and guide tube 2 withintube 3. The outer end of the closure tube 3 is made airtight by a plug 5inserted therein. The rod 1a is longer than the guide tube 2 and extendsbeyond the outer end thereof. A cylindrical soft iron magnet core '6surrounds, and is attached to, the outer end of rod 1a. A similar core 7surrounds, and is attached to, the outer end of guide tube 2.

An airtight and yet flexible connection'between the closure tube 3 andcell wall 33 is provided by a multiconvolution bellows 9. One end of thebellows is sealed by brazing to an adaptor plate 19 which, in turn, isremovably fastened to the cell wall 33. An O-ring 10 provides a sealbetween plate 19 and wall 33. The other end of the bellows 9 is sealedby brazing to an adaptor ring 18. This ring 18 is removably secured to aterminal plate 17 by screws 26, only one of which is shown. Plate 17 issealed by brazing to the outer surface of the closure tube 3. A sealbetween ring 18 and plate 17 is provided by an O-ring 11.

In order to eliminate undue strain on the bellows 9, a gimbal-likestructure is provided by a ring 20 surrounding the bellows 9. Ring 20 issupported on four pins 8, two of which, in turn, mate through washers 24into a pair of blocks 21, only one of which is shown, attached toterminal plate 17 by screws 25. The other two pins 8 mate throughwashers 24 into a pair of blocks 22, only one of which is shown,attached to adaptor plate 19 by screws 25. Thus the enclosure tube 3 maybe non-rotatably pivoted about a point in the center of ring 20 toprovide side-to-side and up-and-down motion, or a combination thereof,of the tong fingers 1.

Rotary and axial motion of the tong fingers 1, as well as opening andclosing of the fingers 1, is accomplished by movement of at least aportion or all of four circular magnets 31, 31a and 30, 30a, whichencircle the outer extremity of closure tube 3. The magnets 30, 39a areenclosed in a sleeve 12 and restrained therein with a pair of washers16a, 1611. A plate 13 completes the housing. The magnets 31, 31a areenclosed in a similar sleeve 14 and are restrained therein with washers15, 16. A repulsive force is applied between the magnet assemblies by aspring 32. The maximum separation of the assemblies is established by aplurality of adjustable indexing studs 28, only one of which is shown.Studs 28 pass through sleeve member 14 and threadably engage sleevemember 12. Lock nuts 29 are provided to prevent studs 28 from rotatingonce they have been adjusted to provide the desired spacing between themagnet assemblies.

The magnet assemblies are slidable along the enclosure tube 3 but areprevented from disengagement therewith by a washer 23 releasably securedto the plug 5 by a screw 27. It can be seen in the figure that themaximum spacing between the magnet assemblies is chosen so that theyrespectively encircle the magnetic core 6 attached to the rod 1a and themagnetic core 7 attached to the guide tube 2. The value of this maximumspacing is chosen to cause the tong rod 1a to be drawn into the guidetube 2 to a maximum distance so as to close fingers 1. The fingers 1 maythen be opened by moving the magnet assemblies, and thus the magneticcores 6, 7 toward each other so as to move the tong rod 1a axiallywithin guide tube 2.

The tong fingers may be moved further into the cell by movement of theentire magnet assembly toward the cell Wall 33, and withdrawn bymovement of the entire magnet assembly in the reverse direction. Thetong fingers may be rotated about the axis of the tong rod It: byrotating the magnet assemblies about the axis of the closure tube 3.Also, as discussed above, limited up-anddown and side-to-side motion ofthe tong fingers 1 may be made by movement of the closure tube 3 inthose planes. It may thus be seen that the above manipulator may bemoved with little limitation without the use of sliding or rotatingseals, since the rod 1a, sleeve 2, and the magnetic cores 6, 7 aresealed within closure tube 3 so that the problems of leaks areessentially eliminated.

This invention has been described by way of illustration rather thanlimitation and it should be apparent that other changes in thearrangement of the various parts of my invention as shown and describedmay be resorted to without departing from the spirit of the invention orthe scope of the appended claims.

What is claimed is: a

1;, An improved remotely operated manipulator for use in an enclosedcell provided with a manipulator opening and containing radioactivematerials, comprising an elongated rod provided with fingers on one end,a sleeve shorter than and slidably fitted on said rod, a tubular memberenclosing said rod and its sleeve and coaxially spaced therefrom, abushing positioned in one end of said tubular member, said bushinghaving a central opening which acts as a slidingbearing for said sleeve,a plug disposed in the other end of said tubular member, means forsupporting and for flexibly sealing said one end of said tubular memberwithin said opening in said cell, said fingers and a portion ofsaid rodand one end of said sleeve extending into said cell, a first magneticfollower aifixed to the other end of said rod, a second magneticfollower affixed to the other end of said sleeve, a first sleeve memberslidable upon said tubular member, a first permanent magnet disposed insaid first sleeve member and positioned in a magnetic coupling relationto said first magnetic follower, a second sleeve member slidable uponsaid tubular member, a second permanent magnet disposed in said secondsleeve member and positioned in a magnetic coupling relation to saidsecond magnetic follower, means for coupling said sleeve memberstogether, said coupling including resilient means disposed between saidsleeve members, said resilient means acting in cooperation with saidmagnetic couplings for urging said sleeve against the base ends of saidfingers to hold them closed, said resilient means adapted to becompressed by movement of said sleeve members toward each other toeffect relative movement between said rod and sleeve by means of saidmagnetic couplings to thereby open said fingers, said rod and sleevebeing manually movable in unison along the axis and rotatable about theaxis of said rod relative to said tubular member by action of saidmagnets upon said followers to thereby effect movement of saidmanipulator to a plurality of selected longitudinal and axial positions.

2. The manipulator set forth in claim 1, wherein a third permanentmagnet is disposed in said first sleeve member and in a magneticcoupling relation to said first magnetic follower, and a fourthpermanent magnet is disposed in said second sleeve member and in amagnetic coupling relation to said second magnetic follower.

References Cited in the file of this patent UNITED STATES PATENTS892,162 Kennedy June 30, 1908 2,290,226 Du Mond July 21, 1942 2,320,967Dunkelberger June 1, 1943 2,405,127 Beach Aug. 6, 1946 2,595,134 GordonApr. 29, 1952 2,659,569 Ehlke Nov. 17, 1953 2,665,789 Ingersoll Jan. 12,1954 2,697,356 Knudsen Dec. 21, 1954 2,719,485 Bendar Oct. 4, 19552,752,625 Ponsell July 3, 1956

